Add board name defines to board/variant-specific include file

What change would like to see?

Include a #define NAME_OF_BOARD (or #define BOARD NAME_OF_BOARD, etc. ) in the 
pins_arduino.h file for each board/variant supported. The exact form is not 
critical, but there should be some standard for e.g. libraries to detect which 
Arduino board they are targeting when necessary (other than guessing wildly by 
detecting the ATmega flavor). Set this standard and the world will (hopefully) 
follow :-)

Why?

Currently, there is no way for an Arduino library to detect or make provisions 
for a specific board, which is often done to provide board-specific features or 
implement custom digital (usually 'fast') I/O pin mapping functions. (This is 
unfortunately common practice even in well-known libraries such as sdfatlib.) 
Library authors currently try to guess with #ifdefs for various ATmega CPU 
names, but this is a poor substitute for targeting actual board variants, and 
does not handle cases where multiple variants use the same CPU.

Would this cause any incompatibilities with previous versions?  If so, how
can these be mitigated?

None that I can see.

Original issue reported on code.google.com by drmn...@gmail.com on 9 May 2012 at 4:52

Merged into: #308

folpindo / arduino

Add board name defines to board/variant-specific include file #912